Bacteria break down lignin with enzymes (Introduction)

by David Turell , Thursday, January 07, 2016, 15:45 (3024 days ago)

Again the use of naturally produced enzymes to break down living material:-http://www.sciencedaily.com/releases/2016/01/160106143032.htm-"The original goal was to design a single new enzyme that could do the job of several found in nature. But that turned out to be an impossible task, in part because lignin molecules are irregular. They're made of hundreds of components that twist either to the left or the right, but the pattern of twists doesn't repeat, and an enzyme that's tailored to break a left-handed bond won't cleave a right-handed one.-"'Making a single enzyme would be like trying to make a glove that's designed for your left hand fit on your right hand," said Kate Helmich, co-lead author of the study and a recent Ph.D. graduate of UW-Madison's Biochemistry Department. "Our two hands are different configurations of the same fingers, and lignin is like a chain of many different hands. Degrading that entire chain would require an enzyme, or glove, that can attach to both the left and the right hands within it."-"The researchers found that Sphingobium bacteria use two enzymes, known as LigE and LigF, to attack lignin as a team.-"'The key finding is that we now understand how the left-hand and the right-hand versions are broken," Phillips said. "It's not through a single super enzyme but through teamwork where you've got one for the left and one for right.-"It wasn't clear how the bacteria did it until Donohue and his team made both the left-handed and right-handed compounds, and then assayed them with purified enzymes. Those experiments proved that one works on left and one works on right."-Comment: Biomimetics at work. How did the bacteria find or invent these enzymes to use? Chance or design?